Hardening machine

ABSTRACT

A machine for hardening workpieces has a treatment tank formed at its top with an entrance opening for a heated workpiece to be immersed in cooling liquid upon insertion into the tank; a pair of curved gripper jaws are mutually reciprocable inside the tank to engage the workpiece, their displacement toward each other coinciding with a closure of the entrance opening as well as of an inlet and an outlet for the liquid. The inlet and outlet form part of a circulation system including a liquid reservoir above the tank and a catch basin beneath it. Gases evolving from the liquid in the treatment tank are allowed to escape into an exhaust duct via ports flanking the entrance opening.

United States Patent [191 Macovei HARDENING MACHINE [75] Inventor: Nicolae Macovei, Craiova, Romania [73] Assignee: Uzina Constructii Masini Agricola NOEMBRIE,, Craiova, Romania [22] Filed: Jan. 24, 1972 [21] Appl. No.: 219,984

Primary Examiner-Lowell A. Larson Attorneyl(arl F. Ross [57 7 ABSTRACT A machine for hardening workpieces has a treatment tank formed at its top with an entrance opening for a heated workpiece to be immersed in cooling liquid upon insertion into the tank; a pair of curved gripper jaws are mutually reciprocable inside the tank to engage the workpiece, their displacement toward each other coinciding with a closure of the entrance opening as well as of an inlet and an outlet for the liquid. The inlet and outlet form part of a circulation system including a liquid reservoir above the tank and a catch basin beneath it. Gases evolving from the liquid in the treatment tank are allowed to escape into an exhaust duct via ports flanking the entrance opening.

9 Claims, 2 Drawing Figures FIELD OF THE INVENTION My present invention relates to a machine for hardening workpieces, particularly thin pieces of large surface area, in water or oil between gripper jaws which may also serve to deform the workpieces being hardened.

BACKGROUND OF THE INVENTION Conventional machines of this general type include lower and upper dies between which the workpiece is gripped in a horizontal position while being immersed in the cooling liquid, as by being depressed against the force of a coil spring supporting the lower die.

OBJECTS OF THE INVENTION The general object of my invention is to provide a machine of the type set forth which is very efficient, does high-quality work and is easy to operate.

A more particular object is to provide a machine of this character in which the workpiece is uniformly cooled on both surfaces, an effect not realizable with horizontally positioned workpieces.

SUMMARY OF THE INVENTION In accordance with the present invention I provide a treatment tank whose top has an entrance opening for a workpiece to be hardened, this tank also having an inlet and an outlet for fresh and spent cooling liquid, respectively. The workpiece introduced from above into the tank is engaged by gripper means movable into and out of an operating position by actuating means such as a pair of pneumatic cylinders with doubleacting pistons on diaphragms. The same actuating mechanism controls first shutter means for blocking the inlet and second shutter means for blocking the outlet in the workpiece-engaging or operating position of the gripper means; the tank may also be provided with third shutter means, controlled by the actuating mechanism, for blocking the entrence opening in the workpiece-engaging position of the gripper means.

BRIEF DESCRIPTION OF THE DRAWING The above and other features of my invention will now be described indetail with reference to the accompanying drawing in which:

FIG. 1 is a front view of a machine embodying my invention; taken partly in section on line I l of FIG. 2; and

FIG. 2 is a side view of the machine.

SPECIFIC DESCRIPTION The machine shown in the drawing comprises a prismatic treatment tank 1 whose two halves are held together by a set of screws 2. The top of the tank has an entrance opening a for the introduction of a thin, flat workpiece 28 receivable between a pair of gripper jaws 3' and 3" which are slidably mounted on horizontal rods 4 spanning the two tank halves. Jaw 3 is designed as a concave die with a generally vertical face of serrated honeycomb profile confronting the jaw 3", the latter being a complementarily convex die whose working face also has a serrated honeycomb profile. The serrations of these faces form intersecting channels facilitating the circulation of cooling liquid on opposite sides of the workpiece. The ends of the rods 4, on which the inserted workpiece 28 comes to rest, are threaded and engaged by nuts 5 securing them to the tank walls with the requisite fluidtightness.

The tank ll rests on a rigid frame 8 carrying a pair of mounting brackets 7 whose mutual spacing can be adjusted; these brackets support respective pneumatic cylinders 8 having piston rods 10 projecting therefrom into the tank 1 as carriers for the jaws 3, 3".

Piston rods 10 are provided with arms 9 linking these rods with an upper pair of horizontally slidable shutters 33, an intermediate pair of shutters 34 and a lower pair of shutters 34, all mounted on respective rods 11 which slide in bearings on the tank walls. The coupling between rods 10 and the upper shutters 33 also includes coil springs 38. The shutters 33, lying close to the top of the tank, obstruct the entrance opening a upon movement of the jaws 3, 3" toward each other into their workpiece-engaging position. At the same time, the shutters 34 block a pair of inlets b for cooling liquid and an outlet 0 for that liquid; inlets b communicate via conduits 12 with a reservoir 18 above tank 1 whereas outlet c drains via a filter 13 into a catch basin 14 underneath the tank from which the spent liquid can be discharged through a pipe 15. An overflow pipe 16 terminates within reservoir 18 in a threaded sleeve 17 which can be adjusted to vary the liquid level therein, as observed through a sight glass 22. Reservoir l8, supported on brackets 20, receives fresh liquid under suitable pressure from a supply conduit 21. Another sight glass 23 enables observation of the liquid level in treatment tank 21.

A manual lever 25 operates a slide valve 24 to control the admission of compressed air, via flexible tubes 27, to the actuation cylinders 8. Conduits 36 and 37 interconnect corresponding chambers of the two cylinders. The compressed air is fed to valve 24 through a pipe 26.

The top of tank 1 is also shown provided with a pair of venting ports d, flanking the entrance opening a, which communicate by way of a pair of channels 29 with an exhaust duct 30 for evolving gases. This duct is al 0 provided with a hood 31, overhanging the reservoir? l8, and with a connection 31 to the catch basin 14.

As will be readily apparent from FIG. 1, apertures a, b and c are unblocked in the illustrated position in which the jointly reciprocable jaws 3 and 3" are separated. Upon movement of the jaws toward each other, these apertures are blocked by their respective shutters 33, 35; venting ports d are not obstructed during the shaping operation. As the jaws move apart to release the treated workpiece 28, the same can be withdrawn from the tank even as the spent liquid is discharged through outlet 0 while fresh liquid from reservoir 18 enters through inlets b. The filling level of the tank, as observed with the aid of gauge 23, can be regulated through proper adjustment of the shutters.

I claim:

1. A machine for the treatment of workpieces in a cooling liquid, comprising:

a treatment tank having a top provided with an entrance opening for a heated workpiece, said tank having an inlet and an outlet for said cooling liquid;

supply means for said cooling liquid connected to said inlet;

drain means for spent cooling liquid connected to said outlet;

gripper means in said tank engageable with a workpiece introduced through said entrance opening;

actuating means for moving said gripper means into and out of a workpiece-engaging position;

first shutter means for blocking said inlet;

second shutter means for blocking said outlet; and

coupling means linking said first and second sutter means with said actuating means for blocking said inlet and outlets upon movement of said gripper means into said workpiece-engaging position,

2. A machine as defined in claim 1, further comprising third shutter means linked with said actuating means for blocking said entrance opening upon movement of said gripper means to said workpiece-engaging position.

3. A machine as defined in claim 2, further comprising exhaust means for gases evolving from the liquid in said tank, said top having at least one venting port communicating with said exhaust means.

4. A machine as defined in claim 3 wherein said supply means includes a reservoir above said tank, said drain means including a catch basin below said tank, said reservoir and said basin being provided with venting connections to said exhaust means,

5. A machine as defined in claim 3 wherein said venting port is duplicated on opposite sides of said entrance opening.

6. A machine as defined in claim 1 wherein said gripper means comprises a pair of jaws with confronting generally vertical faces mounted for joint horizontal reciprocation toward and away from each other.

7. A machine as defined in claim 6 wherein said first and second shutter means each comprise a pair of shutters respectively linked with said jaws.

8. A machine as defined in claim 6 wherein said jaws are provided at said faces with complementarily curved profiles.

9. A machine as defined in claim 8 wherein said profiles have serrations forming passages for said liquid therebetween. 

1. A machine for the treatment of workpieces in a cooling liquid, comprising: a treatment tank having a top provided with an entrance opening for a heated workpiece, said tank having an inlet and an outlet for said cooling liquid; supply means for said cooling liquid connected to said inlet; drain means for spent cooling liquid connected to said outlet; gripper means in said tank engageable with a workpiece introduced through said entrance opening; actuating means for moving said gripper means into and out of a workpiece-engaging position; first shutter means for blocking said inlet; second shutter means for blocking said outlet; and coupling means linking said first and second shutter means with said actuating means for blocking said inlet and outlets upon movement of said gripper means into said workpiece-enGaging position.
 2. A machine as defined in claim 1, further comprising third shutter means linked with said actuating means for blocking said entrance opening upon movement of said gripper means into said workpiece-engaging position.
 3. A machine as defined in claim 2, further comprising exhaust means for gases evolving from the liquid in said tank, said top having at least one venting port communicating with said exhaust means.
 4. A machine as defined in claim 3 wherein said supply means includes a reservoir above said tank, said drain means including a catch basin below said tank, said reservoir and said basin being provided with venting connections to said exhaust means.
 5. A machine as defined in claim 3 wherein said venting port is duplicated on opposite sides of said entrance opening.
 6. A machine as defined in claim 1 wherein said gripper means comprises a pair of jaws with confronting generally vertical faces mounted for joint horizontal reciprocation toward and away from each other.
 7. A machine as defined in claim 6 wherein said first and second shutter means each comprise a pair of shutters respectively linked with said jaws.
 8. A machine as defined in claim 6 wherein said jaws are provided at said faces with complementarily curved profiles.
 9. A machine as defined in claim 8 wherein said profiles have serrations forming passages for said liquid therebetween. 